CROWES NeoBird1-060726.qxp 2/8/06 2:41 pm Page 42

>> IDENTIFICATION WORKSHOP MANTLED Field identification of polionotus Sergio H. Seipke, Douglas Kajiwara and Jorge B. L. Albuquerque

antled Hawk Leucopternis polionotus is a photographs and video taken in the wild. Adults largish buteonine considered Near were studied on more than 20 occasions at MThreatened3 that inhabits humid forests, Urubici, Santa Catarina, Brazil, in July 2003 and second growth and Paraná Pine Araucaria June 2006, and a juvenile was observed, by DK, at angustifolia mixed woodland, from sea level to at General Carneiro, Paraná, Brazil, on 25 May 2003. least 1,500 m, recorded from Alagoas to Rio I. Accordi recorded bare-parts coloration for three Grande do Sul in eastern and southern Brazil20, wild individuals, two adults and one of unknown north-east Argentina6,16, east Paraguay5,8 and, age, in Rio Grande do Sul, Brazil, and G. S. perhaps, northern Uruguay10. However, there are Cabanne photographed an adult held at São Paulo no documented records from Argentina, Uruguay zoo, Brazil. Though we have studied specimens, or Paraguay. Of four sight records in north-east we report only plumage details observable in the Argentina since 197514, one involved a field. We also provide information to distinguish misidentified pair of White-tailed other raptors sympatric with Mantled Hawk. albicaudatus (C. Saibene pers. comm.) and no published details are available for the others. One was reportedly observed along the lower río Descriptions Carapá, eastern Paraguay9 in 1989, but no details Perched adult (Plate 1, Figs. 1d,f,g; 3) Appears were given. chunky, with broad ‘shoulders’ relative to total The reportedly replaces White-necked length. White head looks large, round and Hawk L. lacernulatus above 500 m1,2,5,8,13, but conspicuous; markings around eyes afford a Mantled Hawks are observed from sea level, and masked appearance. Cere and lores ash-grey to White-necked Hawks have been seen as high as dull yellow; bill has paler grey base grading to 900 m (R. Fadini & R. Parrini pers. comm.; SHS & black at tip. Irides brown in good light, otherwise DK pers. obs.). Habitat use and relative abundance appear black. Underparts unmarked white. along altitudinal gradients are poorly understood Mantle, scapulars and tertials slaty grey with for Mantled Hawk. broad white tips affording a somewhat scaled Though several field guides depict and pattern. Slate-black upperwing-coverts appear describe this hawk, none of these permits swift darker than scapulars. Secondaries dark lead grey and confident identification in the field, and some with 3–4 narrow darker bands (in good views) and are inaccurate in iris and facial skin coloration, broad white tips form a shallow U if seen from relative proportions, the position of the wingtips behind. Secondaries reach halfway to tail tip, relative to the tail tip, and flight silhouette. concealing rump and base of tail. Primaries black Accurate field identification is necessary to with greyer bases and thin white tips reach or produce better information on its distribution, slightly exceed tail tip, sometimes forming a small ecology and habitat requirements, which in turn dark triangle below tail. Usually only the white are required to develop an appropriate part of the tail is visible, but in some individuals conservation strategy4. one, rarely two, dark bands are just visible at the tail base. Tail tip square. Tarsi yellow and usually partially concealed; toes strong and orangish Methods yellow. Plumage descriptions, illustrations and behavioural patterns reported here are from field Perched juvenile (Plate 1, Fig. 1e) Very much like observations, careful notes taken while observing adult but dark streaks on crown and nape visible through binoculars and telescopes, and at distance. Upperwing-coverts fringed whitish.

42 Neotropical Birding 2006 CROWES NeoBird1-060726.qxp 1/8/06 2:16 pm Page 43

Cere whitish to dull yellow. Somewhat marbled 1, Figs. 1a–b). Note, dark tail base seldom visible. dark bars at base of tail more numerous and Note ill-defined two-toned underwing pattern and noticeable than in adults. white leading edge to wings. Wings held either level, on a shallow dihedral, or slightly cupped Flying birds (Plate 1, Figs. 1a,b; 4) Very unique (Plate 1, Figs. 1c, 4). silhouette with long, very broad, rounded wings and short tail. White head appears bulky and Perched White square tail and white U formed sometimes (in females?) projects further than tail. by secondary tips unique and eliminate other Wings longer than body and tail-length in soaring raptors. Wingtips reach or slightly exceed tail tip birds (wingspan 2.6˘ total length). Broad white (Fig. 3). White tips to dorsal feathers very trailing edge to wings conspicuous in good light noticeable and make birds, especially juveniles, (especially if backlit, but not obvious in cloudy appear scaled from behind (Plate 1, Figs. 1d–e). conditions). All-white tail appears squarish if Front on, look for the white tail (Plate 1, Fig. 1g). folded, slightly wedged when partially fanned, and These field marks are noticeable at long distance rounded when fully fanned. Dark base of tail and suffice to separate all sympatric raptors, seldom noticeable. Seen from behind or if tail fully perched or in flight. fanned, wings and tail form continuous trailing edge. Dark distal half of remiges contrasts with rest of underside, but border ill-defined, especially Similar species on secondaries. Leading edge to wings noticeably Several other ‘black-and-white’ raptors in south- white. Legs not very apparent. east Brazil, north-east Argentina and eastern Paraguay could be confused with Mantled Hawk. Behaviour Perches on exposed branches or bare Silhouette shape, and tail and trailing edge snags in upper half of living trees, but also on dead coloration are the most important characters to ones15 (I. Roesler pers. comm.). In hilly areas, we note in flying birds, whereas tail and secondary tip usually found it on the upper half of forested coloration should be noted in perched birds. slopes. Perches quite straight with tarsi barely White-necked Hawk (Plate 1, Figs. 2a, 5, 6) is visible. Tail often held vertical or slightly forwards. not always easily separated from Mantled Hawk Soars in circles, usually on level wings—but might and is sympatric at several localities5,8,10,13. This hold wings above the horizontal in full soar— species also perches exposed on conspicuous frequently and for long periods, low over forest or, perches and soars above the forest like Mantled mostly, high from mid morning until late Hawk. The white head, dark dorsum, mainly white afternoon. Once height attained, usually glides tail and rounded wings make it overall similar to long distances on somewhat ‘cupped’ wings. Long Mantled Hawk. In flight White-necked Hawk is broad wings give species a very conspicuous flight relatively shorter winged and has a noticeable as birds seem to float in midair. Flapping shallow black subterminal band on the longer tail (Plate 1, and ‘flexible.’ Birds flap very infrequently when Figs. 2a, 6). It soars with wings held above the soaring. One was observed hunting a horizontal (dihedral) resembling a pale-morph (15–20-cm long) from a perch; the glided and adult Buteo polyosoma. The white caught it on the ground, immediately passed the head projects less from the body than the tail. prey to the bill, then took off and soared in wide Though the underwing pattern is two-toned, as in circles; the prey was consumed on the wing, Mantled Hawk, the dark terminal band to the before perching and still-hunting again. We secondaries is well defined, forming a dark (not observed flocks of Chopi Blackbird Gnorimopsar white) trailing edge to the wing. The dorsal chopi, Golden-winged Cacique Cacicus surface lacks the white U on the secondaries in chrysopterus and Epaulet Oriole Icterus perched birds. The whitish bases (not tips) to the cayennensis near to hawks, even on the same mantle, back and scapulars make them appear perch, without mobbing or chasing the raptor. blotched (rather than scaled) from behind; tertials are dark-tipped. White-necked Hawks might also show a masked appearance, but lores are whitish Field marks and other useful characters or creamy, the cere and gape dull yellow, resulting In flight Look for the broad, white trailing edge in an overall paler face pattern. Wingtips fall short to the wings and tail (Plate 1, Figs. 1a, 4), which of tail tip when perched. The dark bands at the appears translucent against the sun. Long base of the undertail are usually concealed by the secondaries make the tail appear very short (Plate long coverts in perched birds, and not easy to

Neotropical Birding 2006 43 CROWES NeoBird1-060726.qxp 1/8/06 2:16 pm Page 44

Plate 1. Mantled Hawk Leucopternis polionotus (1) in Figure 1d. Perched adult (yellowish cere). White head comparison to adult White-necked Hawk L. lacernulatus and neck conspicuous. Chunky body. Secondary tips (2) (not to scale). Arrowheads denote important field reach halfway to tail tip and form noticeable white U. marks, long arrows subsidiary characters useful in the Note white tips to body feathers on dorsal surface. field (Aldo Chiappe) Primaries reach or slightly exceed tail tip. Dark base of Figure 1a. Soaring bird against blue sky. Short all-white white tail seldom visible. tail and white trailing edge to wings diagnostic. Short Figure 1e. Juvenile. Upperwing-coverts fringed buff or tail barely projects beyond trailing edge to wings. whitish. Bands on tail base noticeable. Note dark Greyish parts to remiges somewhat contrast with rest of streaks on top of head and lower hindneck. White tips underwing. Chunky body. Note smooth curve to leading to secondaries diagnostic. edge of wings. Figure 1f. Head. Dark eyes, greyish facial skin and grey Figure 1b. Gliding against cloudy sky. Appears darker. to black bill afford ‘masked’ appearance (some White trailing edge inconspicuous. Long secondaries individuals have yellowish cere). almost conceal short squarish tail. Note smooth curves Figure 1g. Detail of tail and wingtips in front view. Note formed by ‘wrists.’ orangish toes. Figure 1c. Tail view silhouettes. Glides with wings Figure 2a. Soaring White-necked Hawk. Wings relatively somewhat cupped, and soars with wings level or slightly shorter and more rounded than Mantled Hawk. Black upheld. bands to trailing edge of wings and on tail diagnostic. Head projects from body less than the tail.

44 Neotropical Birding 2006 CROWES NeoBird1-060726.qxp 1/8/06 2:16 pm Page 45

Figure 4. Adult Mantled Hawk Leucopternis polionotus, Santa Catarina, Brazil, July 2006; white trailing edge to wings and tail diagnostic, and note ill-defined two-toned underwing pattern and white leading edge to wing (Sergio H. Seipke)

Figure 3. Adult Mantled Hawk Leucopternis polionotus, Santa Catarina, Brazil, July 2006; note white tips to secondaries and wingtip reaching beyond tail tip, but dark tail base is seldom visible (Sergio H. Seipke)

Figure 6. Adult White-necked Hawk Leucopternis lacernulatus, São Paulo, Brazil, July 2006; wings held above the horizontal (dihedral), whilst white leading edge and sharply defined trailing edge to wings and subterminal black tail band are diagnostic; dark base of tail hard to see in the field (Sergio H. Seipke)

Figure 5. Adult White-necked Hawk Leucopternis Figure 7. Pale-morph adult Short-tailed Hawk Buteo lacernulatus, São Paulo, Brazil, July 2006; note dark brachyurus, Misiones, Argentina, June 2006; wings are (not white) tips to secondaries, primaries fall short of held level when soaring, and note relatively pointed tail tip, tail is white and has conspicuous black wings, barred tail and, most importantly, dark cheeks subterminal band (Sergio H. Seipke) (Sergio H. Seipke)

Neotropical Birding 2006 45 CROWES NeoBird1-060726.qxp 1/8/06 2:16 pm Page 46

>> IDENTIFICATION WORKSHOP MANTLED HAWK

distinguish from the dark trailing edge on a Canevari et al.6 and Ferguson-Lees & Christie8). moving bird, although obvious in flight pictures Most we observed perched upright, but the tarsi (Fig. 6). An all-white head, dark and sharply were invisible or partially concealed; we consider defined trailing edge to the wings and subterminal that perched shapes resembling spp., dark tail band are diagnostic. as in de la Peña & Rumboll18 or Ferguson-Lees & Gliding or seen from behind, Mantled Hawk Christie8, are inadequate, but Plate 88 in Brown & resembles Black-chested - Amadon5 agrees well with our observations. The melanoleucus or a King Vulture secondaries are broadly white-tipped and reach Sarcoramphus papa, but if followed for some halfway along the tail (contra Brown & Amadon5, period the pointed wings and wedge-shaped tail of de la Peña & Rumboll18, del Hoyo et al.10 and the buzzard-eagle, or the black tail and noticeable Narosky & Yzurieta16). The dark bands at the base ‘fingers’ of the vulture will become apparent. Both of tail were usually invisible, perched or in flight species have dark heads. The vulture even soars (not as in Brown & Amadon5, Canevari et al.6, on flat wings—or on a very shallow dihedral—but Ferguson-Lees & Christie8, del Hoyo et al.10, the primaries are much more curved upwards, and Narosky & Yzurieta16, Olrog17 and de la Peña & the underwing pattern sharply defined. Rumboll18,), making it naïve to hope to identify Adult White-tailed Hawks have ill-defined Mantled Hawk using this character. The primaries two-toned underwings but soar with the wings reach or exceed the tail tip when perched (as in de held in a strong dihedral, have long pointed wings la Peña & Rumboll18 and Olrog17, but contra and, most importantly, a dark subterminal band Brown & Amadon5, del Hoyo et al.10 and on the tail. The head- and neck-sides are dark Ferguson-Lees & Christie8). The irides of all adults grey, and the rufous lesser upperwing-coverts, we studied were dark brown (not yellow, as in de white uppertail-coverts, rump and lower back are la Peña & Rumboll18 and Olrog17). We failed to easily seen from above in adult White-tailed Hawk note the often-mentioned blackish shaft-streaks (but absent in Mantled Hawk). Immature White- on the head of adults, even in those observed at tailed is marked below and / or black-hooded. close range (<100 m) through scopes, but such Short-tailed Hawk Buteo brachyurus (pale streaking is noticeable in juveniles. morph) soars on flat wings7, has two-toned Brown & Amadon5, Canevari et al.6, de la Peña underwings but a much longer, dark-tipped tail, & Rumboll18, del Hoyo et al.10 and Narosky & and conspicuous dark cheeks (Fig. 7). Yzurieta16 mentioned or depicted the cere as being Swallow-tailed Kite Elanoides forficatus—with either yellow, yellowish or pale yellow. An adult in its forked tail—is unmistakable, but attention must São Paulo zoo had the cere and upper half of the be paid to perched birds as they show white on lores dull yellow in January and August 2005. the scapulars, and the tail is often concealed by Three caught in Rio Grande do Sul during the foliage. This species has grey toes and tarsus austral summer also had yellow ceres (I. Accordi (seldom visible). pers. comm.). Ferguson-Lees & Christie8 stated that specimens they studied seemed to have grey ceres. All those we observed in winter at Urubici Discussion had greyish lores but a yellow cere above the Given our small sample size, the images presented nostrils. Some individual variation in facial skin here should not be considered as definitive of colour is documented, but whether this relates to Mantled Hawk, but we believe that the age, gender or geography is unknown. Season is illustrations and field marks highlighted above will unlikely to account for variation in cere coloration permit swift and confident identification of the since the individual at the São Paulo zoo had a species. yellow cere throughout the year. We found some inconsistencies in the It seems unlikely that Mantled Hawk will be literature. Mantled Hawks glide on rather level overlooked by trained observers surveying a wings (not forming a dihedral as in Narosky & suitable area for any length of time. Mañosa & Yzurieta16). Due to the long secondaries, the tail Pedrocchi12 reported this raptor as more appears extremely short in flight (not as in frequently observed than any other in Fazenda Canevari et al.6, de la Peña & Rumboll18, Ferguson- Intervales, São Paulo, Brazil, and we detected Lees & Christie8 and Narosky & Yzurieta16). The Mantled Hawks within 1–2 days at localities we secondaries contrast with the underwing-coverts, surveyed. Birds soar frequently throughout the sometimes resembling a King Vulture or those day and are easy to find when perched at distances Buteo species with two-toned underwings (contra over 1 km, as they usually select exposed

46 Neotropical Birding 2006 CROWES NeoBird1-060726.qxp 1/8/06 2:16 pm Page 47

positions. Furthermore, birds can be quite vocal in 7. Clark, W. S. & Wheeler, B. K. (2001) Hawks of North human presence. In other words, Mantled Hawks America. Second edn. Boston, NY: Houghton are easily detected where present. The lack of Mifflin. recent records from well-watched areas in 8. Ferguson-Lees, J. & Christie, D. A. (2001) Raptors of Misiones, Argentina11,19 (E. R. Krauczuk pers. the world. London, UK: Christopher Helm. comm.) and Paraguay (J. Mazar Barnett pers. 9. Hayes, F. E. & Tamayo, T. G. (1992) Bird densities comm.) makes us suspect the species no longer along three tributaries of the Paraná River in eastern occurs in either region. Paraguay. El Hornero 12: 254–256. Sight records based only on field marks listed 10. del Hoyo, J., Elliott, A. & Sargatal, J. (eds.) (1994) in previous publications should be treated with Handbook of the birds of the world, 2. Barcelona: caution. Detailed field notes, listing all observed Lynx Edicions. field marks, should be published for sight records 11. Krauckzuk, E. R. & Baldo, J. D. (2004) Contribución of this Near Threatened species. al conocimiento de la avifauna de un fragmento de selva con Araucaria en Misiones, Argentina. ACKNOWLEDGEMENTS Atualidades Orn. 119: 6–43. 12. Mañosa, S. & Pedrocchi, V. (1997) A raptor survey in We are especially grateful to Aldo Chiappe for his the Brazilian Atlantic rainforest. J. Raptor Res. 31: marvellous plate. Pedro Develey, Rodrigo Fadini, Ricardo 203–207. Parrini and Ignacio Roesler shared unpublished data. In addition to their own data, Iury Accordi, G. Sebastián 13. Martuscelli, P. (1996) Hunting behaviour of the Cabaña and Fábio Raposo provided photographs of wild Mantled Hawk (Leucopternis polionota) and White- and captive birds. G. Sebastián Cabanne and Ricardo necked Hawk (L. lacernulata) in southern Brazil. Pereira photographed captive hawks on request. Gustavo Bull. Brit. Orn. Club 116: 114–116. Trainini assisted our field work. Alejandro Riccheri, 14. Mazar Barnett, J. & Pearman, M. (2001) Annotated Ignacio Roesler, Paula & Randy Stack, and the American checklist of the birds of Argentina. Barcelona: Lynx Birding Association’s Birder’s Exchange Program Edicions. provided optical equipment. Early drafts benefited from 15. Mitchell, M. H. (1957) Observations on birds of comments by Keith L. Bildstein, G. Sebastián Cabanne, southeastern Brazil. Toronto: University of Toronto William S. Clark, Guy Kirwan, Fábio Olmos and Ignacio Press. Roesler. Juliana Notarnicola provided additional 16. Narosky, T. & Yzurieta, D. (1994) Guía para la materials and field work was partly supported by Bill identificación de las aves de Argentina y Uruguay. Clark and Elisabeth DeVries. This is contribution no. 1 Buenos Aires: Vasquez Mazzini. of the ‘Projeto Gaviões de Penacho do Sul do Brasil.’ We 17. Olrog, C. C. (1984) Las aves argentinas: una nueva will be most grateful for comments on the usefulness of guía de campo. Buenos Aires: Administración de the field marks proposed, and on the accuracy of the Parques Nacionales. flight silhouettes presented here. 18. de la Peña, M. R. & Rumboll, M. (1998) Birds of REFERENCES southern South America and Antarctica. Princeton, NJ: Princeton University Press. 1. Albuquerque, J. B. L. (1986) Conservation and status 19. Seipke, S. H. & Cabanne, G. S. (2002) Rapaces of raptors in southern Brazil. Birds of Prey Bull. 3: observadas en un área selvática de San Pedro, 88–94. Misiones, Argentina. Orn. Neotrop. 13: 273–282. 2. Albuquerque, J. B. L. (1995) Observations of rare 20. Sick, H. (1985) Ornitologia brasileira. Brasília: Ed. raptors in southern Atlantic rainforest of Brazil. J. Universidade de Brasília. Field Orn. 66: 363–369. 3. BirdLife International (2004) Threatened birds of the world 2004. CD-ROM. Cambridge, UK: BirdLife SERGIO H. SEIPKE, DOUGLAS KAJIWARA AND International. JORGE B. L. ALBUQUERQUE 4. Bierregaard, R. O. (1998) Conservation status of c/o Calle 57 1230A, La Plata (1900), Buenos Aires, birds of prey in the South American tropics. J. Argentina. E-mail: [email protected] Raptor Res. 32: 19–27. 5. Brown, L. & Amadon, D. (1968) , hawks, and falcons of the world. Secaucus, NJ: The Wellfleet Press. 6. Canevari, M., Canevari, P., Carrizo, G. R., Harris, G., Rodríguez Mata, J. & Straneck, J. (1991) Nueva guía de aves argentinas, 1. Buenos Aires: Fundación Acindar.

Neotropical Birding 2006 47